Method of reducing nitrogen oxide emissions

ABSTRACT

A method of reducing nitrogen oxide emissions, the method comprising
         (i) injecting a petroleum-derived diesel fuel composition having:
           (a) a sulfur content of less than 10 ppm;   (b) a flash point of greater than 50° C.;   (c) a UV absorbance, A total , of less than 1.5 as determined by the formula comprising   
               

         A   total   =A   x +10( A   y )                 wherein A x  is the UV absorbance at 272 nanometers; and   wherein A y  is the UV absorbance at 310 nanometers;       (d) a naphthene content of greater than 5 percent;   (e) a cloud point of less than −12° C.;   (f) a nitrogen content of less than 10 ppm; and   (g) a 5% distillation point of greater than 300 F and a 95% distillation point of greater than 600 F, in an advanced combustion engine;       (ii) combusting the petroleum-derived diesel fuel in (i) in a combustion chamber of a non-spark ignited engine, wherein nitrogen oxide emissions are lower than those nitrogen oxide emissions when a conventional diesel fuel is employed in a non-spark ignited engine.

FIELD OF THE INVENTION

The present invention is directed to a method of reducing nitrogen oxide(NO_(x)) emissions in diesel fueled internal combustion engines.Reduction of NO_(x) emissions is achieved when a premium diesel fuelcomposition is employed in the combustion chamber of an HCCI engine at adesignated compression ratio or in the combustion chamber of a heavyduty diesel engine at standardized federal test procedures.

BACKGROUND OF THE INVENTION

Un-combusted diesel fuel, including ultra-low sulfur diesel (ULSD), hasa strong odor. The odor often associated with diesel is unpleasant andmay deter customers from purchasing diesel vehicles. In particular, thediesel fuel, when spilled, especially on one's hands or clothing, mayhave a prolonged bad odor. Also diesel fuel stored in equipmentcontained in garages, basements, sheds, or even houses can emit an odorthat may make it undesirable to store the equipment or fuel indoors.

Several factors lead to diesel fuel odor. Eliminating only some of thefactors can result in a diesel fuel that still has an unacceptable odor.Understanding and controlling most or all the factors is necessary toachieve a fuel that has a truly low odor level or no odor. Anotherimportant consideration is that when the odor causing components areeliminated from the prospective fuel it may no longer meet all therequired specifications for the fuel. Only by careful balancing of thefactors can a fuel be produced that both has low odor and meets dieselfuel specifications.

Additionally, emissions, especially NO_(x) emissions, from vehiclesutilizing diesel are also relatively high. The current approach inreducing NO_(x) to levels that meet governmental environmentalregulations is to use exhaust aftertreatment systems (such as SelectiveCatalyst Reduction Systems or NO_(x) traps) that convert engine-outNO_(x) to less harmful species such as N₂. However, these systems arenot always the best solution because they may (1) be costly, (2) add tothe weight of the vehicle, (3) require addition of chemicals such asurea, and (4) hurt fuel economy due to the added weight and the need toburn additional fuel to regenerate the NO_(x) conversion components. Useof the premium, odorless diesel product of the present invention willproduce less engine-out NO_(x), thus enabling less frequentregenerations, and/or a reduction in size or elimination of theaftertreatment system. Further, older vehicles which do not haveextensive aftertreatment equipment should have lower emissions with thispremium, odorless diesel product.

It has been discovered that some key factors in reducing or eliminatingdiesel fuel odor are adjusting the aromatic content, adjusting theamounts of volatile and low-boiling point compounds, and controlling theamount of sulfur and other heteroatoms in the diesel fuel. It has alsobeen discovered that this low/no odor diesel fuel, when employed incertain engine environments, results in low NO_(x) emissions.

DESCRIPTION OF THE RELATED ART

Murakami et al., U.S. Pat. No. 5,730,762 teach a diesel fuel of reducedsulfur content which contains an alkyl side chain on the aromatic ringand also contains hetero nitrogen compounds with an alkyl side chain.The composition also includes carbazole and indole compounds ascomponents of the fuel composition.

Nikanjam et al., U.S. Pat. No. 5,389,112 disclose a diesel fuel with lowaromatic content and high cetane number. There are controlled amounts ofaromatics in the fuel to produce an optimum cetane number as defined bya graph set forth in the patent. The fuel can also have added thereto acetane improver. The composition also includes 2-ethyl-hexylnitrate asthe cetane improver.

Russell U.S. Pat. No. 5,792,339 discloses a diesel fuel which minimizesthe production of pollutants from vehicles by adjusting the amounts ofaromatic compounds in the fuel. The composition also includes polycyclicaromatics of between 5.0 to 8.6 weight %.

Hubbard et al., U.S. Pat. No. 6,096,103 teach the use of mineral spiritswith low sulfur and low odor in diesel engines.

Hubbard et al., U.S. Pat. No. 6,291,732 teach a diesel fuel comprising ablend of aromatic and aliphatic mineral spirits having a low sulfurcontent for use in cold climates.

Ellis et al., U.S. Pat. No. 6,893,475 disclose a distillate fuel havinga sulfur level of less than about 100 wppm, a total aromatics content ofabout 15 to 35 wt. %, a polynuclear aromatics content of less than about3 wt. %, wherein the ratio of total aromatics to polynuclear aromaticsis greater than about 11.

While low sulfur diesel fuels and low emissions diesel fuels are knownin the art, diesel fuels specifically formulated to have low or no odorthrough the reduction of sulfur, nitrogen, aromatic, and volatilecompounds are novel.

SUMMARY OF THE INVENTION

In one embodiment, the present invention is directed to a method ofreducing nitrogen oxide emissions, the method comprising

-   -   (i) injecting a petroleum-derived diesel fuel composition        having:        -   (a) a sulfur content of less than 10 ppm;        -   (b) a flash point of greater than 50° C.;        -   (c) a UV absorbance, A_(total), of less than 1.5 as            determined by the formula comprising

A _(total) =A _(x)+10(A _(y))

-   -   -   -   wherein A_(x) is the UV absorbance at 272 nanometers;                and            -   wherein A_(y) is the UV absorbance at 310 nanometers;

        -   (d) a naphthene content of greater than 5 percent;

(e) a cloud point of less than −12° C.;

-   -   -   (f) a nitrogen content of less than 10 ppm; and        -   (g) a 5% distillation point of greater than 300 F and a 95%            distillation point of greater than 600 F, in an advanced            combustion engine;

    -   (ii) combusting the petroleum-derived diesel fuel in (i) in a        combustion chamber of a non-spark ignited engine, wherein        nitrogen oxide emissions are lower than those nitrogen oxide        emissions when a conventional diesel fuel is employed in a        non-spark ignited engine.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 depicts the volumetric percent of exhaust gas recycled to theengine for the diesel fuel employed in the invention and for thecomparative diesel fuels.

FIG. 2 depicts the nitrogen oxide emissions from an HCCI engine when thetwo comparative diesel fuels and the diesel fuel of the invention areemployed.

FIG. 3 depicts the nitrogen oxide emissions from a heavy duty dieselengine when the two comparative diesel fuels and the diesel fuel of theinvention are employed.

FIG. 4 depicts the carbon dioxide emissions from a heavy duty dieselengine when the two comparative diesel fuels and the diesel fuel of theinvention are employed.

FIG. 5 depicts a process of making an odorless diesel fuel composition.

FIG. 6 depicts one embodiment of a process of making an odorless dieselfuel composition.

FIG. 7 depicts one embodiment of a process of making an odorless dieselfuel composition.

FIG. 8 further depicts another embodiment of the process for making anodorless diesel fuel composition.

FIG. 9 depicts the correlation between odor, aromatic content and flashpoint.

FIG. 10 depicts the correlation between flash point as determined byPensky-Marten, ASTM D93 and 5% initial boiling point as determined byASTM D2187.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof are herein described indetail. It should be understood, however, that the description herein ofspecific embodiments is not intended to limit the invention to theparticular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention as defined by the appended claims.

Definitions

HCCI Engine—Homogenous Charge Compression Ignition engine. The fuel/airmixture that is used in these engines is homogenous. The fuel ignitesupon suitable compression of the fuel/air mixture

Diesel Engine—The fuel/air mixture that is used is a stratified mixturewherein the fuel is concentrated in one area of the cylinder. Typically,the fuel ignites upon suitable compression of the stratified mixture.

HDT—refers to “hydrotreater.”

HDC—refers to “hydrocracker.”

IDW—refers to “dewaxing.”

Hydrogenation/hydrocracking catalyst may also be referred to as“hydrogenation catalyst” or “hydrocracking catalyst.”

The terms “feed”, “feedstock” or “feedstream” may be usedinterchangeably.

The term “heteroatom” refers to any atom that is not carbon or hydrogen.Typical heteroatoms include, but are not limited to, nitrogen, sulfur,phosphorus, and oxygen.

The term “UV” refers to ultraviolet wavelengths of light in the range ofabout 10 nanometers to about 400 nanometers.

All elemental group notations (e.g., Group VIII) refer to CAS Notation.

Method of Reducing Nitrogen Oxide Emissions

One embodiment of the present invention is directed to reducing nitrogenoxide (NOx) emissions in a non-spark ignited engine when apetroleum-derived diesel fuel composition, as described hereinbelow, isemployed in a non-spark ignited engine. Nitrogen oxide emissions aredecreased when compared to the nitrogen oxide emissions when aconventional diesel fuel composition is employed in a non-spark ignitedengine.

It has been discovered that NOx emissions decrease when thepetroleum-derived diesel fuel composition described hereinbelow is usedin a non-spark ignited engine (e.g., heavy duty diesel engine andadvanced combustion engine).

In one embodiment, the diesel fuel composition described herein below isinjected into an advanced combustion engine, preferably a homogenouscharge compression ignition (HCCI) engine; the diesel fuel compositionis then combusted in the advanced combustion engine and from about 20volume percent to about 55 volume percent is recycled to the combustionchamber and the nitrogen oxide emissions are less than 0.45 g/kWh.

It has also been discovered that the nitrogen oxide emissions vary atcertain HCCI engine operating conditions. (See FIG. 2) The following hasbeen discovered:

TABLE A NOx Emissions at Various HCCI Engine Operating Conditions EngineLoad, Bar Revolutions Per Exhaust Gas NOx Emissions BMEP Minute (RPM)Recycle (EGR) g/kWh 3 1500 50% Less than 0.25 6 1500 30-40%   Less than0.3 7 1750 Approx. less than Less than 0.38 35% 6 2000 Approx. less thanLess than 0.5 35% 8 2250 Approx. less than Less than 0.4 30%

It has also been discovered that nitrogen emissions are lower when thepetroleum-derived diesel fuel composition, which is describedhereinbelow, is employed in a heavy duty diesel engine than when aconventional diesel fuel composition is employed in a heavy duty dieselengine at the same operating conditions.

In one embodiment, the engine is a heavy duty diesel engine. NOxemissions were determined based upon heavy duty federal test procedures(FTP)¹ which are herein incorporated by reference. At FTP Hot, NOxemissions for the petroleum-derived diesel fuel composition, describedhereinbelow, was less than 4.5 g/hp-hr. At FTP Cold, NOx emissions forthe petroleum-derived fuel composition, described hereinbelow, was lessthan 5.0 g/hp-hr. By comparison, for two different conventional dieselfuel compositions, NOx emissions were greater than 4.5 g/hp-hr at FTPHot and greater than 5.3 g/hp-hr at FTP Cold. (See FIG. 3). ¹ The FTP(Federal Test Procedure) heavy-duty transient cycle is currently usedfor emission testing of heavy-duty on-road engines in the USA [CFR Title40, Part 36.1333] . . . The FTP transient test is based on the UDDSchassis dynamometer driving cycle.https://www.dieselnet.com/standards/cycles/ftp_trans.html

At FTP Hot, CO₂ emissions for the petroleum-derived diesel fuelcomposition, described hereinbelow, was less than 530 g/hp-hr. At FTPCold, CO₂ emissions for the petroleum-derived fuel composition,described hereinbelow, was less than 550 g/hp-hr. By comparison, for twodifferent conventional diesel fuel compositions, CO₂ emissions weregreater than 530 g/hp-hr at FTP Hot and greater than 550 g/hp-hr at FTPCold. (See FIG. 4).

Diesel Fuel Composition

A diesel fuel composition comprises various compounds including sulfurcompounds, nitrogen compounds, aromatic compounds and volatile compounds(light ends). In order to achieve a low or no odor diesel fuel, it hasbeen discovered that heteroatom-containing compounds, aromatic content,and volatile light ends need to be reduced.

Elimination of most of the sulfur compounds that make up the diesel fuelcomposition results in a diesel fuel that has reduced odor. Furthermore,if the diesel fuel composition has some sulfur compounds, the type ofsulfur compound will dictate whether the diesel fuel composition has astrong odor. The total sulfur content of the diesel fuel composition ofthe invention is less than 10 ppm; more preferred, less than 6 ppm; andmost preferred, less than 3 ppm.

Another type of heteroatom which can impart an odor to diesel fuel isnitrogen. Nitrogen containing compounds can be organic compounds such asaliphatic or aromatic hydrocarbons with a nitrogen containingsubstitutent or inorganic nitrogen containing compounds such as ammoniumcompounds, nitrates, and nitrites. Accordingly, the diesel fuelcomposition of the invention may have a nitrogen content of less than 10ppm; more preferred, less than 5 ppm; and most preferred, less than 1ppm.

Aromatic compounds are other compounds that have also been found tocontribute to diesel fuel odor. It has been discovered that reduction ofthe aromatic content of the fuel can also greatly reduce the odor of thefuels. As with sulfur and nitrogen compounds, the species of aromaticcompounds in the fuel can have an effect on the odor, but generally ithas been found that a diesel fuel composition with very low totalaromatic levels has a decreased odor.

Aromatic content may also be approximated by the UV absorbance atspecific wavelengths, namely at 272 and 310 nm. Aromatic compoundstypically absorb ultraviolet (UV) wavelengths of light in the range of272 nanometers (nm) and 310 nanometers (nm). Accordingly, the sum of UVabsorbances, given as A_(total), is related to the aromatic content of agiven diesel fuel. We have found that A_(total) as given in the formula

A _(total) =A ₂₇₂+10(A ₃₁₀)

wherein A₂₇₂ is the UV absorbance at 272 nm and wherein A₃₁₀ is the UVabsorbance at 310 nm, must be less than about 1.5, preferably less thanabout 1.0, and most preferably less than about 0.8 to have the odorlessdiesel fuel composition of the present invention.

In an embodiment of the present invention, the total aromatic compoundcontent of the fuel is less than 10%, preferably less than 7.5%, morepreferably less than 5%, most preferably less than 2%, even morepreferred less than 1%, and even most preferred less than 0.5%. Aromaticcontent was measured using Supercritical Fluid Chromatography (SFC),ASTM D5186.

By measuring the A_(total) of a given feedstock, the degree in which tohydrotreat is determined in order to produce a low odor diesel fuel.

Still yet another factor that has been found to be important or criticalin achieving a low or no odor fuel is the amount of the volatile orlight boiling components in the fuel. These components are oftenreferred to as light ends or “front end” of the diesel fuel range. Ithas been found that by decreasing the light boiling components of thediesel fuel, in combination with decreasing the other components listedabove, a low or no odor diesel fuel can be obtained. One useful measurefor evaluating the front end of the diesel fuel is using the 5% initialboiling point and 95% final boiling point of the fuel as measured byASTM D2887. In the present invention, the 5% initial boiling point ofthe fuel should be greater than 300 degrees F., preferably greater than320 degrees F., more preferably greater than 340 degrees F., and mostpreferably greater than 375 degrees F. The 95% final boiling point ofthe diesel fuel composition of the present invention is greater than600° F., preferably, greater than 675 degrees F., more preferred,greater than 725 F. Another measure for evaluating the volatility of thediesel fuel is the boiling point. Preferably the boiling point range ofthe diesel fuel composition of the present invention is from about 300°F. to about 730° F.

The flash point of the diesel fuel composition of the present inventionhas a flashpoint within diesel specifications. Preferably the flashpoint is greater than about 50° C., preferably, greater than about 55°C., more preferred greater than 60° C., even more preferred greater thanabout 70° C., and most preferred greater than 75° C. as measured by thePensky-Martin closed cup method.

The cloud point refers to the temperature below which solids, such aswax, start to precipitate in the diesel fuel leading to a cloudyappearance. The cloud point is an important measure of the coldtemperature characteristics of a diesel fuel. The diesel fuel of thepresent invention has a cloud point less than −12° C.

The diesel fuel composition of the present invention will be low inaromatic compounds. The feedstock prior to hydrotreating may contain asignificant amount of aromatic species. For example, the feedstock priorto hydrotreatment may contain at least 5% aromatics. The feedstock maycontain at least 10% aromatics or the feedstock may contain at least 20%aromatics. During hydrotreatment, the aromatics can be, at least inpart, converted to napthenes by hydrodearomatization reactions. Inaccordance with the present invention, the naphthene content of thediesel fuel composition of the present invention is greater than 5%. Thenaphthenes may be formed from hydrodearomatization of the feedstockduring hydrotreatment or the naphthenes may be present in the feedstockprior to hydrotreatment as long as the diesel fuel composition of thepresent invention has a naphthene content of greater than 5%.

In one embodiment of the present invention, the diesel fuel compositioncomprises a sulfur content of less than 6 ppm, a flash point of greaterthan or equal to 60° C., a nitrogen content of less than 10 ppm, a 5%distillation point of greater than 300° F. and a 95% distillation pointof greater than 600° F. , a cloud point of less than −12° C., anaphthene content of greater than 5%, and an aromatic content, as givenby A_(total), of less than 1.5.

In another embodiment of the present invention, the diesel fuelcomposition comprises a sulfur content of less than 6 ppm, a flash pointof greater than or equal to 60° C,a nitrogen content of less than 10ppm, a 5% distillation point of greater than 300° F. and a 95%distillation point of greater than 600° F. , a cloud point of less than−12° C., a naphthene content of greater than 5%, and an aromaticcontent, as given by A_(total), of less than 1.0.

In another embodiment of the present invention, the diesel fuelcomposition comprises a sulfur content of less than 6 ppm, a flash pointof greater than or equal to 60° C,a nitrogen content of less than 10ppm, a 5% distillation point of greater than 300° F. and a 95%distillation point of greater than 600° F. , a cloud point of less than−12° C., a naphthene content of greater than 5%, and an aromaticcontent, as given by A_(total), of less than 0.8.

The diesel fuel of the present invention, in addition to thecharacteristics noted above, may, in some embodiments, comprise othercharacteristics such as viscosity. The viscosity is a measure of theresistance to flow of the diesel fuel, and it will decrease as thediesel fuel oil temperature increases. If the diesel fuel is used in adiesel engine, for example, the viscosity of the diesel fuel must be lowenough to flow freely at its lowest operational temperature, yet highenough to provide lubrication to any moving parts in the engine.Viscosity also will determine the size of the fuel droplets, which, inturn, govern the atomization and penetration qualities of the fuelinjector spray. In one embodiment, the diesel fuel of the presentinvention may have a viscosity at 40° C. of less than 4.1 mm/cSt asmeasured by ASTM D445-64.

The diesel fuel of the present invention, may, in some embodiments,comprise other characteristics such as net heat of combustion asdetermined by ASTM D4868. Preferably the diesel fuel of the presentinvention will have a net heat of combustion greater than 18,000 Btu/lband more preferably more than 18,500 Btu/lb. It should be noted thatviscosity and net heat of combustion describe the characteristics ofsome embodiments of the diesel fuel composition of the presentinvention. Not all embodiments of the diesel fuel composition of thepresent invention need to possess one or more of these physicalcharacteristics. Moreover, the physical characteristics outside thepreferred ranges are still within the scope of the invention asdescribed and claimed herein.

If desired, the diesel fuel composition of the present invention mayinclude additives to improve the lubricity of the diesel fuelcomposition. When used in a diesel engine, for example, some dieselfuels, especially low sulfur content fuels, offer limited protectionagainst engine wear. The wear occurs to the injector needle due torubbing contact with the surface of its container. Also, various partsof fuel pumps such as internal gears and cams are subject to wear due tofuel related problems. In some embodiments, to increase the diesel fuellubricity, one or more lubricity enhancing additives can be mixed withthe diesel fuel. Typically, the concentration of the lubricity enhancingadditive in the fuel falls in the range of from about 1 to about 50,000ppm, preferably about 10 to about 20,000 ppm, and more preferably fromabout 25 to about 10,000 ppm. Any lubricity enhancing additives can beused. These lubricity enhancing additives include, but are not limitedto, fatty alcohols, fatty acids, amines, ethoxylated amines, boratedesters, other esters, phosphates, phosphites, phosphonates, and mixturesthereof.

Method of Making the Diesel Fuel Composition

As discussed herein, several hydrotreating or hydrogenation or bothmethods (generally, hydroconversion method) may be employed to produce adiesel composition having low or no odor. A suitable hydroconversionmethod is determined based upon the aromatic content of thehydrocarbonaceous feedstock.

In one embodiment, both a hydrotreating catalyst (base metal) and ahydrogenation catalyst (noble metal) are employed to produce the dieselcomposition described hereinabove.

A hydrocarbonaceous feedstock having at least 50 ppm sulfur and at least25 percent by weight aromatic content is fed to a hydrotreater over ahydrotreating catalyst thereby producing a hydrotreated product.

Hydrotreating catalysts are suitable for hydroconversion of feedstockscontaining high amounts of sulfur, nitrogen and/or aromatic-containingmolecules. Such catalysts generally contain at least one metal componentselected from non-noble Group VIII (CAS Notation) or at least one metalcomponent selected from the Group VIB (CAS notation) elements ormixtures thereof. Group VIB elements include chromium, molybdenum andtungsten. Group VIII elements include iron, cobalt and nickel. Theamount(s) of metal component(s) in the catalyst suitably range fromabout 0.5% to about 25% by weight of Group VIII metal component(s) andfrom about 0.5% to about 25% by weight of Group VIB metal component(s),calculated as metal oxide(s) per 100 parts by weight of total catalyst,where the percentages by weight are based on the weight of the catalystbefore sulfiding. The metal components in the catalyst may be in theoxidic and/or the sulphidic form. If a combination of at least a GroupVI B and a Group VIII metal component is present as (mixed) oxides, itmay be subjected to a sulfiding treatment prior to proper use inhydrotreating. Suitably, the catalyst comprises one or more componentsof nickel and/or cobalt and one or more components of molybdenum and/ortungsten.

The hydrotreating catalyst particles of this invention are suitablyprepared by impregnating, blending, or co-mulling, active sources of theaforementioned metals with a support or binder. Examples of suitablesupports or binders include silica, alumina, clays, zirconia, titania,magnesia and silica-alumina. Preference is given to the use of aluminaas a support or a binder or both. Other components, such as phosphorous,may be added as desired to tailor the catalyst particles for a desiredapplication. When co-mulling, the blended components are then shaped,such as by extrusion, dried and calcined at temperatures up to 1200° F.(649° C.) to produce the finished catalyst particles. Alternatively,equally suitable methods of preparing the amorphous catalyst particlesinclude preparing oxide binder particles, such as by extrusion, dryingand calcining, followed by depositing the aforementioned metals on theoxide particles, using methods such as impregnation. The catalystparticles, containing the aforementioned metals, are then further driedand calcined prior to use as a hydrotreating catalyst.

Suitable hydrotreating catalysts generally comprise a metal component,suitably Group VIB or VIII metal, for example cobalt-molybdenum,nickel-molybdenum, on a porous support, for example silica,silica-alumina, alumina or mixtures thereof. Examples of suitablehydrotreating catalysts are the commercial ICR 106, ICR 120 of ChevronResearch and Technology Co.; DN-200 of Criterion Catalyst Co.; TK-555and TK-565 of Haldor Topsoe A/S; HC-K, HC-P, HC-R and HC-T of UOP;KF-742, KF-752, KF-846, KF-848 STARS and KF-849 of AKZO Nobel/NipponKetjen; and HR-438/448 of Procatalyse SA.

Catalysts used in carrying out hydrotreating operations are well knownin the art. See, for example, U.S. Pat. Nos. 4,347,121 and 4,810,357 forgeneral descriptions of hydrotreating, and typical catalysts used inhydrotreating processes.

The hydrotreating catalyst employed in the present invention is selectedfrom the group consisting of a nickel-molybdenum catalyst, anickel-tungsten catalyst, a molybdenum-tungsten catalyst, anickel-molybdenum-tungsten catalyst and a molybdenum-cobalt catalyst.Preferably, the catalyst employed is a nickel-molybdenum catalyst on analumina support.

The hydrotreated product is then fed to at least one separation unit andseparated into at least two product streams: a first product stream anda second product stream. Preferably, the hydrotreated product isseparated into a naphtha product stream, a jet product stream, and aheavy product stream. Typically, the second product stream or the heavyproduct stream has a sulfur content that is less than 50 ppm by weight.Preferably, the hydrotreated product is fed to at least two separationunits, one of which includes a distillation column. The heavy productstream is then fed to a hydrogenation reactor system. The heavy productstream is fed to the hydrogenation reactor system over a noble metalhydrogenation catalyst, thereby producing a hydrogenated product.Optionally, an isomerization catalyst may be added to the hydrogenationreactor system to control cloud point. The hydrogenated product is thenfed to at least one separation unit thereby producing a naphtha productstream, a jet product stream and a diesel product stream. Preferably,the hydrogenated product is fed to at least one separation unit, one ofwhich may include a distillation column, thereby producing a dieselproduct stream having an aromatic content of less than 7.5 percent byweight, a sulfur content of less than 10 ppm, and a flash point ofgreater than 50 degrees Celsius.

Suitable hydrogenation catalysts generally comprise Group VIII noblemetals or oxides thereof. Platinum catalyst or palladium catalyst ormixtures thereof may be employed. Optionally, a reduced Group VIII basemetal, such a nickel, may be employed as the hydrogenation catalyst.

FIG. 5 further depicts a process of making an odorless diesel fuelcomposition. FIG. 5 illustrates a hydrocarbonaceous feed, entering theprocess through stream 100, combined with stream 110 comprising make-uphydrogen and combined with stream 140 which comprises recycled hydrogento form stream 115. Hydrogen in stream 140 is prepared by compressingthe high pressure separator 20 gas effluent stream 130.

Stream 115 is heated prior to entering the first stage hydroprocessingunit, vessel 10. Vessel 10 is preferably operated as a hydrotreaterwhere the hydrocarbonaceous feed's sulfur is removed to very low levels,preferably <100 ppm, more preferably less than 50 ppm, most preferably<20 ppm. The feed flows downward through at least one bed of catalyst.Preferably, the feed flows through more than one bed of catalyst.

Hydrotreated effluent exits vessel 10 through stream 120 and is flashedin the high pressure separator, vessel 20. This vessel is a simple flashdrum, separating the liquid hydrocarbon from the hydrogen rich recyclegas stream 130. The recycle gas stream 130 is compressed by the recyclegas compressor 30 and recycled to the hydrotreater reactor 10 inlet.

The high pressure liquid effluent stream 150 is reduced in pressurevalve 35 to low pressure, typically, below 60 psig, to form stream 155.Stream 155 is flashed in the low pressure separator, vessel 40. Thisvessel is a simple flash drum separating the liquid hydrocarbon (stream170) from the product gases (stream 160).

The liquid effluent stream 170 is heated and separated into severalstreams including, but not limited to, a diesel or diesel/jet stream instripper 50 to remove the light gases (stream 180) and naphtha (stream190). As an option, the product jet fuel, i.e., having a jet fuelboiling point range, (stream 195) can either be stripped in stripper 50or combined with the diesel (stream 200) boiling range material instream 200 to produce a jet/diesel stream.

The diesel or the jet/diesel stream 200 is pumped to hydrogenationpressure and combined with stream 210 comprising make-up hydrogen andwith stream 240 comprising recycled hydrogen to form stream 215.Hydrogen in stream 240 is prepared by compressing the high pressureseparator gas effluent stream 230.

Stream 215 is heated prior to entering the hydrogenation unit, vessel60. Vessel 60 is preferably operated as a hydrogenation unit, preferablycharged with high activity, noble base metals, where the hydrocarbonfeed's aromatics are saturated to the levels require to make the dieselproduct odorless. The feed flows downward through at least one or morecatalyst beds.

Typically, the catalyst employed in the hydrogenation unit comprisesnoble metals supported on silica or alumina or silica alumina orcombinations of these supports. The catalyst cracking activity may beenhanced by adding zeolites to the catalysts.

Hydrogenated effluent exits vessel 60 through stream 220 and is flashedin the high pressure separator, vessel 70. This vessel is a simple flashdrum, separating the liquid hydrocarbon from the hydrogen rich recyclegas stream 230. The recycle gas stream 230 is compressed with therecycle gas compressor 80 to the pressure of the hydrogenation reactorinlet.

The high pressure liquid effluent stream 250 is reduced in pressure(valve 85) to a low pressure, typically below 60 psig, to form stream255. Stream 255 is flashed in the low pressure separator, vessel 90.This vessel is a simple flash drum separating the liquid hydrocarbon(stream 270) from the product gases (stream 260).

The liquid effluent stream 270 is heated and separated into at least twostreams. To remove the light gases (stream 280), the liquid effluentstream is separated in stripper 95 into (1) naphtha (stream 290), (2)jet fuel (stream 300) and (3) an odorless diesel product (stream 310).By removing the lighter components in the stripper, the flash point israised to meet the odorless diesel limitation of 50° C.

In one embodiment, a hydrocarbonaceous feedstock, having at least 50 ppmsulfur, is fed to a first reactor system (e.g., a hydtrotreating unit)over a hydrtrotreating catalyst as described hereinabove, therebyproducing a hydrotreated product. The catalyst system in thehydrotreating step takes places in a reactor that that has at least tworeactor beds. The first reactor bed comprises at least two catalystlayers comprising a hydrotreating catalyst layer and ahydrotreating/hydrogenation/hydrocracking catalyst layer. Optionally, ahydrodemetallization layer may also be employed in the first reactorbed. The hydrotreated product is then fed to a second reactor bed whichcomprises at least two layers. Preferably, the second reactor bedcomprises a hydrotreating/hydrogenation/hydrocracking catalyst layer, ahydrocracking layer and a hydrotreating layer. The hydrotreated productis fed through second reactor bed over the catalysts layers, therebyproducing a hydrocracked product.

The hydrocracking catalyst employed is typically a base metal containingcatalyst. In general, the hydrocracking catalyst comprises a crackingcomponent and a hydrogenation component on an oxide support material orbinder. The cracking component may include an amorphous crackingcomponent and/or a zeolite, such as a Y-type zeolite, an ultrastable Ytype zeolite, or a dealuminated zeolite. A suitable amorphous crackingcomponent is silica-alumina.

The hydrogenation component of the hydrocracking catalyst is selectedfrom those elements known to provide catalytic hydrogenation activity.At least one metal component selected from the Group VIIIB (CASNotation) elements and/or from the Group VIB (CASNotation) elements aregenerally chosen. Group VIB elements include chromium, molybdenum andtungsten. Group VIIIB elements include iron, cobalt, and nickel. Theamount(s) of hydrogenation component(s) in the catalyst suitably rangefrom about 0.5% to about 30% by weight of Group VIIIB metal component(s)and from about 0.5% to about 25% by weight of Group VIB metalcomponent(s), calculated as metals per 100 parts by weight of totalcatalyst, where the percentages by weight are based on the weight of thecatalyst before sulfiding. The hydrogenation components in the catalystmay be in the oxidic and/or the sulphidic form. If a combination of atleast a Group VIB and a Group VIIIB metal component is present as(mixed) oxides, it will be subjected to a sulfiding treatment prior toproper use in hydrocracking Suitably, the catalyst comprises one or morecomponents of nickel and/or cobalt and one or more components ofmolybdenum and/or tungsten. Catalysts containing nickel and molybdenumor nickel and tungsten are particularly preferred.

The hydrocracking catalyst particles of this invention may be preparedby impregnating, blending, or co-mulling, active sources ofhydrogenation metals with a binder. Examples of suitable binders includesilica, alumina, clays, zirconia, titania, magnesia and silica-alumina.Preference is given to the use of alumina as binder. Other components,such as phosphorous, may be added as desired to tailor the catalystparticles for a desired application. The blended components are thenshaped, such as by extrusion, dried and calcined at temperatures up to1200° F. (649° C.) to produce the finished catalyst particles.Alternatively, equally suitable methods of preparing the amorphouscatalyst particles include preparing oxide binder particles, such as byextrusion, drying and calcining, followed by depositing thehydrogenation metals on the oxide particles, using methods such asimpregnation. The catalyst particles, containing the hydrogenationmetals, are then further dried and calcined prior to use as ahydrocracking catalyst.

The hydrocracked product is then fed to at least one separation unit andseparated into at least two product streams. Preferably, thehydrocracked product is separated into a first product stream and asecond product stream. The first product stream has a boiling pointrange of from about 80° F. to about 450° F. The second product streamhas a boiling point range of from about 450° F. to about 900° F. Thesecond product stream is then fed to at least one reactor. Preferably,the second product stream is fed to at least two reactors, a first andsecond reactor. The first reactor comprises at least one catalyst layer.Preferably, the first reactor comprises at least two catalysts layerswhich comprise a hydrogenation catalyst and an isomerization de-waxingcatalyst to convert the paraffins into iso-paraffins, thereby producinga de-waxed product stream. The de-waxed product stream is then fed tothe second reactor, a hydrofinishing reactor, thereby producing ahydrofinished effluent product stream.

Typically, the isomerization catalyst comprises intermediate pore sizecatalysts. The term “intermediate pore size” refers to an effective poreaperture in the range of from 5.3 angstroms to 6.5 angstroms when theporous inorganic oxide is in the calcined form. Molecular sieves havingpore apertures in this range tend to have unique molecular sievingcharacteristics. Unlike small pore zeolites such as erionite andchabazite, they will allow hydrocarbons having some branching into themolecular sieve void spaces. Unlike larger pore zeolites, such as thefaujasites and mordenites, they can differentiate between n-alkanes andslightly branched alkanes, and larger branched alkanes having, forexample, quaternary carbon atoms.

The effective pore size of the molecular sieves can be measured usingstandard adsorption techniques and hydrocarbonaceous compounds of knownminimum kinetic diameters. See Breck, Zeolite Molecular Sieves. 1974(especially Chapter 8); Anderson, et al., J. Catalysis 58,114 (1979);and U.S. Pat. No. 4,440,871, the pertinent portions of which areincorporated herein by reference.

In performing adsorption measurements to determine pore size, standardtechniques are used. It is convenient to consider a particular moleculeas excluded if it does not reach at least 95% of its equilibriumadsorption value on the molecular sieve in less than about 10 minutes(p/po=0.5; 25° C.).

Intermediate pore size molecular sieves will typically admit moleculeshaving kinetic diameters of 5.3 to 6.5 angstroms with little hindrance.Examples of such compounds (and their kinetic diameters in angstroms)are: n-hexane (4.3), 3-methylpentane (5.5), benzene (5.85), and toluene(5.8). Compounds having kinetic diameters of about 6 to 6.5.ANG. can beadmitted into the pores, depending on the particular sieve, but do notpenetrate as quickly and in some cases are effectively excluded.Compounds having kinetic diameters in the range of 6 to 6.5.ANG.include: cyclohexane (6.0), 2,3-dimethylbutane (6.1), and m-xylene(6.1). Generally, compounds having kinetic diameters of greater thanabout 6.5.ANG. do not penetrate the pore apertures and thus are notabsorbed into the interior of the molecular sieve lattice. Examples ofsuch larger compounds include: o-xylene (6.8), 1,3,5-trimethylbenzene(7.5), and tributylamine (8.1).

The preferred effective pore size range is from about 5.5 to about6.2.ANG.

It is essential that the intermediate pore size molecular sievecatalysts used in the practice of the present invention have a veryspecific pore shape and size as measured by X-ray crystallography.First, the intracrystalline channels must be parallel and must not beinterconnected. Such channels are conventionally referred to as 1-Ddiffusion types or more shortly as 1-D pores. The classification ofintrazeolite channels as 1-D, 2-D and 3-D is set forth by R. M. Barrerin Zeolites, Science and Technology, edited by F. R. Rodrigues, L. D.Rollman and C. Naccache, NATO ASI Series, 1984 which classification isincorporated in its entirety by reference (see particularly page 75).Known 1-D zeolites include cancrinite hydrate, laumontite, mazzite;mordenite and zeolite L.

None of the above listed 1-D pore zeolites, however, satisfies thesecond essential criterion for catalysts useful in the practice of thepresent invention. This second essential criterion is that the poresmust be generally oval in shape, by which is meant the pores mustexhibit two unequal axes referred to herein as a minor axis and a majoraxis. The term oval as used herein is not meant to require a specificoval or elliptical shape but rather to refer to the pores exhibiting twounequal axes. In particular, the 1-D pores of the catalysts useful inthe practice of the present invention must have a minor axis betweenabout 3.9.ANG. and about 4.8.ANG. and a major axis between about5.4.ANG. and about 7.0.ANG. as determined by conventional X-raycrystallography measurements.

The most preferred intermediate pore size silicoaluminophosphatemolecular sieve for use in the process of the invention is SAPO-11.SAPO-11 comprises a molecular framework of corner-sharing [SiO₂]tetrahedra, [AlO₂] tetrahedra and [PO₂] tetrahedra, [i.e., (S_(x) Al_(y)P_(z))O₂ tetrahedral units]. When combined with a Group VIII metalhydrogenation component, the SAPO-11 converts the waxy components toproduce a lubricating oil having excellent yield, very low pour point,low viscosity and high viscosity index. SAPO-11 is disclosed in detailin U.S. Pat. No. 5,135,638, which is hereby incorporated by referencefor all purposes.

Other intermediate pore size silicoaluminophosphate molecular sievesuseful in the process of the invention are SAPO-31 and SAPO-41, whichare also disclosed in detail in U.S. Pat. No. 5,135,638.

Also useful are catalysts comprising an intermediate pore sizenonzeolitic molecular sieves, such as ZSM-22, ZSM-23 and ZSM-35, and atleast one Group VIII metal. X-ray crystallography of SAPO-11, SAPO-31,SAPO-41, ZSM-22, ZSM-23 and ZSM-35 shows these molecular sieves to havethe following major and minor axes: SAPO-11, major 6.3.ANG., minor3.9.ANG.; (Meier, W. H., Olson, D. H., and Baerlocher, C., Atlas ofZeolite Structure Types, Elsevier, 1996), SAPO-31 and SAPO-41, believedto be slightly larger than SAPO-11, ZSM-22, major 5.5.ANG., minor4.5.ANG. (Kokotailo, G. T., et al, Zeolites, 5, 349(85)); ZSM-23, major5.6.ANG., minor 4.5.ANG.; ZSM-35, major 5.4.ANG., minor 4.2.ANG. (Meier,W. M. and Olsen, D. H., Atlas of Zeolite Structure Types, Butterworths,1987).

The intermediate pore size molecular sieve may be used in admixture withat least one Group VIII metal. Preferably the Group VIII metal isselected from the group consisting of at least one of platinum andpalladium and optionally, other catalytically active metals such asmolybdenum, nickel, vanadium, cobalt, tungsten, zinc and mixturesthereof. More preferably, the Group VIII metal is selected from thegroup consisting of at least one of platinum and palladium. The amountof metal ranges from about 0.01% to about 10% by weight of the molecularsieve, preferably from about 0.2% to about 5% by weight of the molecularsieve. The techniques of introducing catalytically active metals into amolecular sieve are disclosed in the literature, and preexisting metalincorporation techniques and treatment of the molecular sieve to form anactive catalyst such as ion exchange, impregnation or occlusion duringsieve preparation are suitable for use in the present process. Suchtechniques are disclosed in U.S. Pat. Nos. 3,236,761; 3,226,339;3,236,762; 3,620,960; 3,373,109; 4,202,996; 4,440,781 and 4,710,485which are incorporated herein by reference.

The term “metal” or “active metal” as used herein means one or moremetals in the elemental state or in some form such as sulfide, oxide andmixtures thereof. Regardless of the state in which the metalliccomponent actually exists, the concentrations are computed as if theyexisted in the elemental state.

The catalyst may also contain metals, which reduce the number of strongacid sites on the catalyst and thereby lower the selectivity forcracking versus isomerization. Especially preferred are the Group IIAmetals such as magnesium and calcium.

It is preferred that relatively small crystal size catalyst be utilizedin practicing the invention. Suitably, the average crystal size is nogreater than about 10.mu., preferably no more than about 5.mu., morepreferably no more than about 1.mu. and still more preferably no morethan about 0.5.mu.

Strong acidity may also be reduced by introducing nitrogen compounds,e.g., NH.sub.3 or organic nitrogen compounds, into the feed; however,the total nitrogen content should be less than 50 ppm, preferably lessthan 10 ppm. The physical form of the catalyst depends on the type ofcatalytic reactor being employed and may be in the form of a granule orpowder, and is desirably compacted into a more readily usable form(e.g., larger agglomerates), usually with a silica or alumina binder forfluidized bed reaction, or pills, prills, spheres, extrudates, or othershapes of controlled size to accord adequate catalyst-reactant contact.The catalyst may be employed either as a fluidized catalyst, or in afixed or moving bed, and in one or more reaction stages.

The intermediate pore size molecular sieve catalyst can be manufacturedinto a wide variety of physical forms. The molecular sieves can be inthe form of a powder, a granule, or a molded product, such as anextrudate having a particle size sufficient to pass through a 2-mesh(Tyler) screen and be retained on a 40-mesh (Tyler) screen. In caseswherein the catalyst is molded, such as by extrusion with a binder, thesilicoaluminophosphate can be extruded before drying, or, dried orpartially dried and then extruded.

The molecular sieve can be composited with other materials resistant totemperatures and other conditions employed in the isomerization process.Such matrix materials include active and inactive materials andsynthetic or naturally occurring zeolites as well as inorganic materialssuch as clays, silica and metal oxides. The latter may be eithernaturally occurring or in the form of gelatinous precipitates, sols orgels including mixtures of silica and metal oxides. Inactive materialssuitably serve as diluents to control the amount of conversion in theisomerization process so that products can be obtained economicallywithout employing other means for controlling the rate of reaction. Themolecular sieve may be incorporated into naturally occurring clays,e.g., bentonite and kaolin. These materials, i.e., clays, oxides, etc.,function, in part, as binders for the catalyst. It is desirable toprovide a catalyst having good crush strength because in petroleumrefining, the catalyst is often subjected to rough handling. This tendsto break the catalyst down into powder-like materials which causeproblems in processing.

Naturally occurring clays which can be composited with the molecularsieve include the montmorillonite and kaolin families, which familiesinclude the sub-bentonites, and the kaolins commonly known as Dixie,McNamee, Georgia and Florida clays or others in which the main mineralconstituent is halloysite, kaolinite, diokite, nacrite or anauxite.Fibrous clays such as halloysite, sepiolite and attapulgite can also beuse as supports. Such clays can be used in the raw state as originallymined or initially subjected to calcination, acid treatment or chemicalmodification.

In addition to the foregoing materials, the molecular sieve can becomposited with porous matrix materials and mixtures of matrix materialssuch as silica, alumina, titania, magnesia, silica-alumina,silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia,silica-titania, titania-zirconia as well as ternary compositions such assilica-alumina-thoria, silica-alumina-titania, silica-alumina-magnesiaand silica-magnesia-zirconia. The matrix can be in the form of a cogel.

The catalyst used in the process of this invention can also becomposited with other zeolites such as synthetic and natural faujasites,(e.g., X and Y) erionites, and mordenites. It can also be compositedwith purely synthetic zeolites such as those of the ZSM series. Thecombination of zeolites can also be composited in a porous inorganicmatrix.

As discussed above, a de-waxed product stream results from contactingthe second product stream with an isomerization catalyst. The de-waxedproduct stream is fed to at least one reactor comprising a noble metalhydrogentation catalyst as described hereinabove. The de-waxed productstream is hydrofinished thereby producing a hydrofinished productstream. The hydrofinished product stream is then fed to at least oneseparation unit and separated into a naptha product stream, a jetproduct stream, a diesel product stream and at least one base oilproduct stream. Preferably, the hydrofinished product stream is then fedto at least one separation unit and separated into a naphtha productstream, a jet product stream, a diesel product stream, a first base oilproduct stream and a second base oil product stream. Preferably, thehydrofinished product stream is fed to at least two separation units,one of which includes a distillation column, and separated into anaphtha product stream, a jet product stream, a diesel product streamand at least one base oil product stream, preferably at least two baseoil product streams, a first base oil product stream and a second baseoil product stream. The diesel product stream has an aromatic content ofless than 7.5 percent by weight, a UV@272 nm+10*UV@310 nm of less than1.5, a sulfur content of less than 10 ppm and a flash point of greaterthan 50° C.

FIG. 6 further depicts one embodiment of a process of making an odorlessdiesel fuel composition. FIG. 6 illustrates a hydrocarbonaceous feedhaving a boiling point range of 550 F to 1000 F. The feed, stream 100,is combined with stream 110, which comprises make- up hydrogen, and withstream 140, which comprises recycled hydrogen, to form stream 115.Hydrogen in stream 140 is prepared by compressing the high pressureseparator 20 gas effluent stream 130.

Stream 115 is heated prior to entering the first stage hydroprocessingunit, vessel 10. Vessel 10 is preferably operated as a hydrotreaterwhere the hydrocarbonaceous feed's sulfur content if decreased to verylow levels. Preferably, the sulfur content is less than 100 ppm. Morepreferred, the sulfur content is less than 50 ppm and most preferred,the sulfur content is less than 20 ppm. The feed flows downward throughat least one or more beds of catalyst, thereby producing a hydrotreatedproduct.

The hydrotreated effluent product exits vessel 10 through stream 120 andis introduced to a second reactor system, a hydrocraker unit, vessel 15.Vessel 15 is preferably operated at hydrocracking operating conditionswhere the effluent's viscosity index is improved to the viscosity indexlevels associated with lubricant oils, preferably from about 98 to about150. The hydrotreated effluent product is contacted with a hydrocrackingcatalyst, thereby producing a hydrocracked product.

The hydrocracked effluent product exits vessel 15 through stream 125 andis flashed in the high pressure separator, vessel 20. This vessel is asimple flash drum, separating the liquid hydrocarbon from the hydrogenrich recycle gas stream 130. The recycle gas stream 130 is compressed inthe recycle gas compressor 130 and recycled to the hydrotreater reactor10 inlet.

The high pressure liquid effluent stream 150 is fed through valve 35 andreduced in pressure to a low pressure, typically below 60 psig, to formstream 155. Stream 155 is flashed in the low pressure separator, vessel40. This vessel is a simple flash drum separating the liquidhydrocarbon, stream 170, from the product gases, stream 160.

The liquid effluent stream 170 is heated and separated into at least twoproduct streams in stripper 50 in order to separate the light end gasesfrom those product streams having a higher boiling point. The separatedproduct streams may include (1) a waxy base oil, (2) a waxy baseoil/diesel stream, (3) jet fuel, stream 195, (4) light end gases, stream180, and (5) naphtha, stream 190. Optionally, the jet fuel productstream, stream 195, may either be stripped in stripper 50 or combinedwith the waxy base oil/diesel boiling range material in stream 200.

The waxy base oil/diesel or the jet/diesel/waxy base oil stream 200 ispumped to a pressure suitable for hydrogenation (e.g., 2000-2700 psi)and combined with stream 210, which comprises make-up hydrogen, and withstream 240, which comprises recycled hydrogen, to form stream 215.Hydrogen in stream 240 is prepared by compressing the high pressureseparator 70 gas effluent stream 230.

Stream 215 is heated prior to entering the first stage of vessel 60.Vessel 60 is preferably operated as an isomerization de-waxing unit.Preferably the beds in the vessel 60 are charged with high activity,noble base metal catalysts, where the stream 200 is isomerized to thelevels required to set the lubricant base oil pour point and as a resultyields a de-waxed product, a diesel fuel composition with excellent coldflow properties.

Applicable catalyst for the isomerization dewaxing unit comprises noblemetals supported over SM-3, SSZ-32 or ZSM-5 or mixtures thereofsupported on alumina, silica, silica alumina or mixtures thereof.

Stream 220 is generally cooled prior to entering a second stagehydrofinishing reaction unit, vessel 65. Vessel 65 is preferablyoperated as a hydrogenation unit, preferably charged with high activity,noble base metal catalysts, where the dewaxed product's aromatic andolefinic hydrocarbons are hydrogenated to the levels required to meetdiesel fuel specifications, including a low odor. The feed flowsdownward through at least one or more beds of catalyst.

Applicable catalysts for the hydrofinishing unit comprise of noblemetals, such as platinum, palladium, and, optionally, high levels of areduced Group VIII base metal such as nickel, supported over alumina,silica, silica alumina or mixtures thereof.

The hydrofinished effluent product stream exits vessel 65 through stream225 and is flashed in the high pressure separator, vessel 70. Thisvessel is a simple flash drum, separating a liquid hydrocarbon effluentstream from the hydrogen rich recycle gas stream 230. The recycle gasstream 230 is fed to the recycle gas compressor 80, where it iscompressed and fed to the isomerization dewaxing reactor.

The high pressure liquid hydrocarbon effluent stream 250 is reduced inpressure (valve 85) to a low pressure, typically below 60 psig, to formstream 255. Stream 255 is flashed in the low pressure separator, vessel90. This vessel is a simple flash drum separating liquid hydrocarboneffluent, stream 270, from product gas effluent, stream 260.

The liquid hydrocarbon effluent stream 270 is heated and separated instripper 95 into a finished lubricating base oil, stream 320, dieselproduct stream 310, jet product stream 295, naphtha product stream 290,and light gases stream 280. By removing the lighter components in thestripper, the flash point is raised to meet the odorless diesellimitation of greater than 50 degrees C.

In one embodiment of the present invention, a hydrocarbonaceousfeedstock having at least 50 ppm sulfur and at least 7.5 percent byweight aromatic content is fed to a reactor system (e.g., hydrogenatingunit) which contains high activity base metal catalysts to hydrogenatethe hydrocarbonaceous feedstock, thereby hydrogenating thehydrocarbonaceous feedstock and producing a hydrogenated product stream.The hydrogenated product stream is fed to at least one separation unit,thereby separating the hydrogenated product stream into at least twoseparate product streams. Preferably, the hydrogenated product stream isseparated in at least two separation units, one of which includes adistillation column. Preferably, the hydrogenated product stream isseparated into at least a naphtha product stream, a jet product streamand a diesel product stream. The diesel product stream has an aromaticcontent of less than 7.5 percent by weight, a sulfur content of lessthan 10 ppm, and a flash point of greater than 50 degrees C.

Preferably, the high activity base metal catalysts employed in thisembodiment comprises Group VI base metal and Group VIII noble metalsupported on an alumina, silica, alumina-silica, other inorganic oxideor zeolite support. Preferably, the catalyst comprises at least 5 wt %Group VIII and 5 wt % Group VI metals. More preferred, the catalystcomprises 6 wt % Ni and 19 wt % Tungsten. Most preferred, the catalystcomprises 20 wt % Ni and 20 wt % Tungsten, and the reactor system has apressure of at least 1000 psi.

The hydrogenation component of the catalyst can a base metal and can beimpregnated into the inorganic oxide, the zeolite or both. In thisapplication, the term “base metal” includes one or more of nickel,cobalt, tungsten or molybdenum. Usually, a combination of base metalsare used, such as nickel or cobalt in combination with tungsten ormolybdenum, and the base metal is usually sulfided or presulfided in thecatalyst when or before the catalyst is put on stream. The term“impregnation” shall mean the addition to a solid of a volume ofsolution not substantially greater than that which can be absorbed bythe solid, and allowing the solution to be absorbed by or on the solid,followed, without an intermediate washing step, by the drying of thesolution onto the solid.

FIG. 7 further depicts one embodiment of a process of making an odorlessdiesel fuel composition. FIG. 7 illustrates a sulfur containinghydrocarbonaceous feedstock stream 100 which may be combined with arecycle diesel stream 310 to form stream 105 which is then combined withstream 110 which comprises make-up hydrogen and with stream 140 whichcomprises recycled hydrogen to form stream 115. Hydrogen in stream 140is prepared by compressing the high pressure separator 20 gas effluent,stream 130.

Stream 115 is heated prior to entering the first stage hydroprocessingunit, vessel 10. Vessel 10 is preferably operated as a hydrotreater forthe removal of both feed sulfur and nitrogen contained in the feedstock.

Suitable catalysts employed in the hydrotreater comprise Group VI basemetals, Group VIII noble metals, or mixtures thereof supported onsilica, alumina, alumina/silica or mixtures thereof. Optionally, thecatalyst cracking activity may be enhanced by adding zeolites. Stream115 is contacted with the aforementioned catalyst(s), thereby producinga hydrotreated product stream effluent.

The hydrotreated product stream effluent exits vessel 10 through stream120 and enters vessel 20 which is preferably operated as a hydrogenationunit, thereby producing a hydrogenated product stream effluent.Preferably, the hydrogenation unit is charged with relatively highlevels of high activity, base metals catalyst, where the hydrotreatedproduct stream's aromatic content is saturated to the levels required tomake the diesel fuel product low in odor, (i.e., an aromatic content ofless than 7.5 percent by weight). The feed flows downward through atleast one or more beds of catalyst.

The hydrogenated product effluent stream exits vessel 20 through stream125 and is flashed in the high pressure separator, vessel 30. Thisvessel is a simple flash drum, separating the liquid hydrocarbon fromthe hydrogen rich recycle gas stream 130. The recycle gas stream 130 iscompressed in the recycle gas compressor and recycled to thehydrogenation reactor.

The high pressure liquid effluent stream 150 is fed through valve 35 andis reduced in pressure (valve 35) to a low pressure, typically below 60psig to form stream 155. Stream 155 is flashed in the low pressureseparator, vessel 40. This vessel is a simple flash drum separating aliquid hydrocarbon effluent steam (stream 170) from the product gases(stream 160).

The liquid hydrocarbon effluent stream 170 is heated and separated intoa diesel product stream or diesel/jet stream product stream in stripper50 to remove the light gases (stream 180), a naphtha product stream(stream 190), jet fuel product stream (stream 200) and a diesel productstream (Stream 300), having a low odor. Optionally, a portion of thediesel product stream, stream 310, may be recycled back to thehydrotreater reactor, hydrogenation reactor or both for improvedsaturation. By removing the lighter components in the stripper, theflash point is raised to meet the odorless diesel limitation of greaterthan 50 degrees C.

In one embodiment of the present invention, a hydrocarbonaceousfeedstock, having less than 100 ppm sulfur and at least 7.5 percent byweight aromatic content, is fed to a reactor system (e.g., hydrogenationunit) which contains high activity noble metal catalysts, therebyhydrogenating the hydrocarbonaceous feedstock and producing ahydrogenated product. Preferably, the high activity noble metal catalystcomprises at least one Group VIII noble metal, such as platinum,palladium or mixtures thereof. More preferred, the high activity noblemetal catalyst comprises greater than 0.5 wt % of at least one noblemetal. Most preferred, the high activity noble metal catalyst comprisesat least 0.5 wt % platinum, at least 0.5 wt % palladium or mixturesthereof. The hydrogenated product is separated in at least oneseparation unit, thereby producing at least two separated productstreams. Preferably, the hydrogenated product is separated in at leasttwo separation units, one of which includes a distillation column.Preferably, the separated product stream is separated into at least anaphtha product stream, a jet product stream and a diesel productstream. The diesel product stream has an aromatic content of less than7.5 percent by weight, a sulfur content of less than 10 ppm and a flashpoint of greater than 50 degrees C.

Preferably, the high activity noble metal catalysts employed in thisembodiment comprises a noble metal that can be impregnated into theinorganic oxide, the zeolite or both. In this application, the term“noble metal” includes one or more of ruthenium, rhodium, palladium,osmium, iridium or platinum. The term “impregnation” shall mean theaddition to a solid of a volume of solution not substantially greaterthan that which can be absorbed by the solid, and allowing the solutionto be absorbed by or on the solid, followed, without an intermediatewashing step, by the drying of the solution onto the solid.

FIG. 8 further depicts another embodiment of the process for making anodorless diesel fuel composition.

FIG. 8 illustrates a low sulfur hydrocarbonaceous feedstock, preferably,having a sulfur content of less than 50 ppm. More preferred, the sulfurcontent is less than 15 ppm. The feedstock, stream 100, may be combinedwith a recycle diesel stream 310 to form stream 105 which is thencombined with stream 110, which comprises make-up hydrogen, and withstream 140, which comprises of recycle hydrogen, thereby forming stream115. Hydrogen in stream 140 is prepared by compressing the high pressureseparator 20 gas effluent stream 130.

Stream 115 is heated prior to entering a hydrogenation reactor, vessel10. Vessel 10 is preferably operated at hydrogenation operatingconditions that are useful for obtaining aromatic saturation.

Suitable catalysts for the hydrogenation reactor are noble base metalssupported on supports comprising silica, alumina, silica alumina ormixtures thereof. The catalyst cracking activity may be enhanced byadding zeolites, which have been described herein. The hydrocarbonaceousfeedstock is fed to the hydrogenation reactor over the catalyst, therebyproducing a hydrogenated product effluent stream.

The hydrogenated product effluent stream exits vessel 10 through stream120 and is flashed in the high pressure separator, vessel 30. Thisvessel is a simple flash drum, separating the hydrogenated liquideffluent product stream into a hydrocarbon stream and a hydrogen richrecycle gas stream 130. The recycle gas stream 130 is compressed in therecycle gas compressor 30 and recycled to the hydrogenation reactorinlet.

The high pressure liquid effluent stream 150 is reduced in pressure(valve 35) to low pressure, typically below 60 psig to form a lowpressure liquid effluent stream, stream 155. Stream 155 is flashed inthe low pressure separator, vessel 40. This vessel is a simple flashdrum separating the liquid effluent stream into a liquid producteffluent stream (stream 170) and a product gas (stream 160).

The liquid hydrocarbon effluent stream 170 is heated and separated intoa diesel product stream or diesel/jet stream product stream in stripper50 to remove the light gases (stream 180), a naphtha product stream(stream 190), jet fuel product stream (stream 200) and a diesel productstream (Stream 300), having a low odor. Optionally, a portion of thediesel product stream, stream 300, may be recycled back to thehydrotreater reactor/hydrogenation reactor or both for improvedsaturation. By removing the lighter components in the stripper, theflash point is raised to meet the odorless diesel limitation of greaterthan 50 degrees C.

Odorless Diesel Benefits

It has also been discovered that use of the odorless diesel fuel,produced from the processes as described herein, provides decreased sootin a combustion chamber compared to soot produced in a combustionchamber when conventional ultra low sulfur diesel is employed.

One embodiment of the invention is directed to a method of reducing sootin an internal combustion engine by employing a diesel fuel compositionproduced by the processes described herein.

Another embodiment of the present invention is directed to a methodreducing soot in an internal combustion engine by employing a dieselfuel composition, wherein the diesel fuel composition has a (1) sulfurcontent of less than 10 ppm; (2) a flash point of greater than 50° C.;(3) a UV absorbance, A_(tota), of less than 1.5 as determined by theformula comprising

A _(total) =A _(x)+10(A _(y))

-   -   wherein A_(x) is the UV absorbance at 272 nanometers; and    -   wherein A_(y) is the UV absorbance at 310 nanometers;

(4) a naphthene content of greater than 5 percent; (5) a cloud point ofless than −12° C.;

(6) a nitrogen content of less than 10 ppm; and (7) a 5% distillationpoint of greater than 300 F and a 95% distillation point of greater than600 F.

It may be deemed that there is a reduction in particulate matter whenthe odorless diesel of the present invention is employed.

Other embodiments will be obvious to those skilled in the art.

The following examples are presented to illustrate specific embodimentsof this invention and are not to be construed in any way as limiting thescope of the invention.

EXAMPLES Example 1

Example 1 corresponds to FIG. 5. The following process was followed toproduce the odorless diesel as illustrated in FIG. 5. Ahydrocarbonaceous feedstock having 10260 ppm sulfur, a boiling range ofabout 257 F to about 759 F and an aromatic content of 31 percent byweight, as measured by SFC (supercritical fluid chromatography ASTMD5186) method, was fed to a reactor, which comprised a catalyst system,having a liquid hourly space velocity (LHSV) of 3.0 1/Hr. The catalystsystem comprised hydrotreating catalysts selected containing a Group VIand Group VIII metals catalysts, which was promoted with phosphorus, ona large surface area alumina, non-acidic support. The total metals were20 wt %. Specifically, the hydrotreating catalyst comprise nickel andmolybdenum, promoted with phosphorus and supported on alumina. Thetemperature of the hydrotreating reactor was 659 F. 320 scf of hydrogenwas consumed. 4700 scfb of hydrogen was recycled to the hydrotreater.The average pressure of the hydrogen was 860 psi. The hydrotreatedproduct was then fed to a hydrogenation unit which comprised ahydrogenation catalyst. The hydrogenation catalyst comprisedplatinum/palladium on a silica/alumina support. The temperature of thehydrogenation reactor was 580 F. 420 scf of hydrogen was consumed. 2915scfb was recycled to the hydrogenation reactor. The average pressure ofthe hydrogen was 1363 psi.

As shown in Table 1, the two stage reaction process resulted in ahydrocarbon product having an odor of less <0.5 and a non-detectablepercent of aromatics in the product stream, which has a boiling range offrom about 403 F to about 768.

TABLE 1 Two Stage Process, Base Metal for Sulfur Removal followed bySingle Stage Process with High Activity Noble Metal Catalysts forAromatic Saturation ID: Hydrogenation Hydrogenation HydrotreaterHydrotreater Reactor Feed Reactor Effluent Feed Conditions EffluentConditions Conditions Conditions Operating Conditions DieselHydrotreater Diesel Hydrogenation Pressure, psig 950 1600 H2 PressureAvg, psi 860 1363 LHSV, 1/Hr 3.0 3.0 Reactor Temperature, F. 659 580Recycle Hydrogen, SCFB 4700 2915 H2 Consumption, SCFB 320 420 Yields:Jet. Vol. % 0.0 3.7 0.0 22.4 Diesel. Vol % 100.0 80.5 100.0 80.5 OdorScale >5.0 >5.0 >5.0 <0.5 Inspections API Gravity 34.3 38.1 38.1 39.1Sulfur, PPM 10260 <6 <6 <6 Viscosity, cSt @ 40 C. 3.709 3.400 3.400 —Cloud Point, C. −5 −5 −5 −10 UV Absorbance: UV@272 + 10UV@310 12.65671.8774 1.8774 0.0038 Cetane Index 52.2 59.1 59.1 60.3 Aromatics, % 31.027.3 27.3 — Mono aromatics 23.9 23.9 23.9 — Polynuclear Aromatics 6.46.4 6.4 — Flash Point, Calc C. 103 77 77 120 Aniline Point, F. 157 170170 192 Net Heat of Combustion, 18,460 18,660 18,660 18,742 D4523,KBTU/lb Distillation, D2887 IBP/5% 257/416 271/357 271/357 403/45510/30% 472/547 397/503 397/503 482/542 50% 579 561 561 577 70/90%617/673 606/684 606/684 618/682 95/EP 698/759 721/759 721/759 711/768Characterization Factor, Kw 11.89 12.17 12.17 12.23

Example 2

Example 2 corresponds to FIG. 6. The following process was followed toproduce the odorless diesel as illustrated in FIG. 6. Ahydrocarbonaceous feedstock was hydrotreated by feeding thehydrocarbonaceous feedstock into a first reactor which comprised severalcatalysts layers dispersed in two reactor beds, thereby producinghydrotreated product. In the first reactor bed, the first layercomprised a demetallization catalyst which comprised nickel andmolybdenum and wass promoted with phosphorus. The second layer comprisedhydrotreating layer as described in Example 1. The third layer compriseda hydrotreating/hydrogenation/hydrocracking catalyst which comprisednickel/molybdenum and was promoted with phosphorus on an aluminasupport. The hydrotreated product, which was the hydrocrackingfeedstock, had at least 19600 ppm sulfur, a boiling range of about 594 Fto about 971 F. The hydrocracking feedstock was fed to the secondreactor bed reactor, which comprised a catalyst system, having a liquidhourly space velocity (LHSV) of 0.7 1/Hr. In the second reactor bed, thefirst catalyst layer comprised ahydrotreating/hydrogenation/hydrocracking catalyst which comprisednickel/molybdenum and was promoted with phosphorus on an aluminasupport. The second layer comprised a hydrocracking catalyst whichcomprised nickel/molybdenum/y-zeolite on a silica/alumina support. Thethird layer comprised another hydrotreating catalyst layer as describedherein. The temperature of the hydrocracking section of the reactor was724 F. The average pressure of the hydrogen was 2700 psi. And, the gasrecycle rate was 5000 scfb. The hydrocracked product, which had aboiling point range of from about 600 F to about 1010 F was separatedinto two products: a waxy 220 N product and a waxy 100 N product. Thewaxy 220 N product had a boiling point range of from about 640 F toabout 1010 F and the waxy 100 N product had a boiling point range offrom about 600 F to about 920 F. The waxy 100 N product was then fed tothe de-waxing reactor which had a temperature of 625 F, therebyproducing a de-waxed product. The de-waxing reactor comprised a catalystcomprising platinum and 60 wt % SSZ-32 on an alumina support. Thede-waxed product was then fed to a hydrofinishing reactor whichcomprised a platinum/palladium catalyst on a silica/alumina support andhad a temperature of 494 F. The hydrofinishing product had a boilingpoint range of from about 240 F to about 900 F. The hydrofinishingproduct was separated into at least 3 product streams:

(1) a 100 N base oil having a boiling point range of from about 595 F toabout 900 F; (2) a 60 N base oil having a boiling point range of fromabout 540 F to about 710 F; and (3) an odorless diesel product having aboiling point range of from about 250 F to about 665 F.

As shown in Table 2, the hydrocracker/de-waxing/hydrofinishing reactionprocess resulted in hydrocarbon product having an odor of <0.5 and lessthan 0.5 weight percent of aromatics in the product stream, which has aboiling range of from about 255 F to about 660.

The odorless diesel product may be additized with a lubricity additivedissolved in xylene at a concentration that does not add odor to thediesel product.

TABLE 2 Multi-Stage Process for Aromatic Saturation and Production ofOdorless Diesel Operation Hydrocracker De-waxer/Hydrofinisher OperatingConditions Pressure, psig 2700 2750 LHSV, 1/Hr 0.7 1.9 Recycle Gas RateSCFB 5000 3000 Temperatures, F. 375 Hydrocracker 724 — IDW — 625 HF —494 Yields, % Odorless Diesel — 3.2 Lube Oil, 60N — 7.5 100N (Waxy 100)(32) 79.1 Waxy 220 (47) — Stream: HDC Feed Waxy 220 Waxy 100 100NProduct 60N Odorless Product Product/ Product Diesel/ DW Feed ProductInspections: Odor Scale — — — — — <0.5 UV@272 + 10 UV@310 — — — — —0.0023 Flash Point, Calc. C. — — — 210 178 81 (78) API Gravity 23.0 32.834.4 33.7 32.5 39.0 Sulfur, PPM 19600 19 5 <0.5 <0.5 <0.5 Nitrogen, PPM896 1.1 0.1 0.1 0.1 0.1 Pour Point, C. — — — −14 −20 −37 Cloud Point, C.— — — −12 −25 −45 Cetane Index 34 44 53 52 52 59 Aromatics, % — — — — —<0.5 Mono aromatics — — — — — <0.5 Polynuclear Aromatics — — — — — <0.5Viscosity, cSt @ 40 C. — — — 20.9 9.4 3.27 @ 100 C. 7.780 5.675 3.6254.165 — — VI 67 120 110 101 60 — Distillation, D2887 IBP/5% 594/672649/719 604/650 601/661 545/589 255/366 10/30% 700/756 745/795 671/717683/728 605/637 404/508 50% 792 829 752 761 656 567 70/90% 825/870861/905 783/826 791/831 671/686 599/630 95/EP 892/971  826/1006 845/914848/891 692/703 641/660 K Factor 11.79 12.66 12.53 12.50 12.05 12.18HDC: Hydrocracker DW: Dewaxing

Example 3

Examples 3A and 3B correspond to FIG. 7. The following process, whichexemplifies Example 3A, was followed to produce the odorless diesel asillustrated in FIG. 7. A hydrocarbonaceous feedstock having 10171 ppmsulfur, a boiling range of about 257 F to about 759 F and an aromaticcontent of at least 31 percent by weight, as measured by SFC(Supercritical Fluid Chromatography, ASTM D 5186), was fed to a reactor,which comprised a multi-layer catalyst system, having a liquid hourlyspace velocity (LHSV) of 0.52 1/Hr. A first layer of the multi-layercatalyst system comprised a nickel/molybdenum layer promoted byphosphorus on an alumina support. And, a second layer of the multi-layercatalyst system comprised a nickel/molybdenum/y-zeolite on asilica/alumina support. The temperature of the reactor was 673 F. 1660scfb of hydrogen was consumed. 8640 scfb of hydrogen was recycled to thereactor. The average pressure of the reactor was 2254 psi. The feedstockwas fed to the reactor over the aforementioned catalysts, therebyproducing a reaction product. The reaction product was distilled intotwo streams: (1) a diesel product stream and (2) a naphtha/jet productstream. The diesel product stream had a sulfur content of 6 ppm; a totalUV absorbance of 0.0052; a boiling point range of from 328 F to about692 degrees F.; and a calculated flashpoint of 72 degrees C. from thefront end distillation.

Example 3B exemplifies a second run of the single stage process usinghigh activity base metal catalysts to produce odorless diesel. Ahydrocarbonaceous feedstock having 10171 ppm sulfur, a boiling range ofabout 257 F to about 759 F and an aromatic content of at least 31percent by weight, as measured by SFC (Supercritical FluidChromatography, ASTM D 5186), was fed to a reactor, which comprised acatalyst system, having a liquid hourly space velocity (LHSV) of 0.521/Hr. The catalyst system comprised a multi-layer catalyst systemcomprising four catalyst layers. The first layer comprised anickel/molybdenum layer promoted by phosphorus on an alumina support.And, a second layer comprised a nickel/molybdenum/y-zeolite catalyst ona silica/alumina support. A third layer comprised anickel/tungsten/y-zeolite catalyst on a silica/alumina support. And, afourth layer comprised a nickel/molybdenum layer promoted by phosphoruson an alumina support. The temperature of the reactor was 673 F. 1710scfb of hydrogen was consumed. 8610 scfb of hydrogen was recycled to thereactor. The average pressure of the reactor was 2254 psi. The feedstockwas fed to the reactor over the aforementioned catalysts, therebyproducing a reaction product. The reaction product was distilled intotwo streams: (1) a diesel product stream and (2) a naphtha/jet productstream. The diesel product stream had a sulfur content of 6 ppm; a totalUV absorbance of 0.0047; a boiling point range of from 296 degrees F. toabout 673 degrees F.; and a calculated flashpoint of 58 degrees C. fromthe front end distillation.

As shown in Table 3, the single stage reaction process resulted in ahydrocarbon product having an odor of less <0.5. The odorless dieselproduct may be additized with a lubricity additive dissolved in xyleneat a concentration that does not add odor to the diesel product.

TABLE 3 Single Stage Process with High Activity Base Metal Catalysts ID:Feed Example 3A Example 3B Operating Conditions and Yields OperatingConditions Pressure, psig 2254 2254 H2 Pressure Avg, psi 2058 2060 LHSV,1/Hr 0.52 0.53 Reactor Temperature, F. 673 673 Recycle Hydrogen, SCFB8640 8610 H2 Consumption, SCF 1660 1710 Recovery, % — 103.5 102.6Yields: Hydrogen, Wt. % −2.36 −2.76 Hydrogen Sulfide, Wt. % 1.08 1.08Ammonia, wt. % 0.01 0.01 Methane/Ethane, Wt. % 0.17 0.16 Propane/Butane,Vol. % 16.5 17.3 Lt. Naphtha, C5/C6, Vol % 15.5 13.6 Naphtha/Jet, Vol. %0.0 42.3 49.1 Diesel, Vol % 100.0 45.1 40.8 Total 100.0 119.4 120.8Product: Feed Diesel Naphtha/Jet Diesel Naphtha/Jet Odor Scale >5.0 <0.5— <0.5 — API Gravity 34.3 42.7 43.4 41.3 41.3 Sulfur, PPM 10171 <6 <6 <6<6 Total UV Absorbance: 12.6567 0.0052 — 0.0041 — UV@272 + 10UV@310Flash Point, Calc. C. 103 72 — 58 — Product Quality Inspections:Hydrogen, Wt. % −2.36 −2.76 Hydrogen Sulfide, Wt. % 1.08 1.08 Ammonia,wt. % 0.01 0.01 Methane/Ethane, Wt. % 0.17 0.16 Propane/Butane, Vol. %16.5 17.3 Lt. Naphtha, C5/C6, Vol % 15.5 13.6 Naphtha/Jet, Vol. % 0.042.3 49.1 Diesel, Vol % 100.0 45.1 40.8 Total 100.0 119.4 120.8 Product:Feed Diesel Naphtha/Jet Diesel Naphtha/Jet Yield, Vol. % 100.0 45.1 42.340.8 49.1 Odor Scale 5.0 <0.5 — <0.5 — API Gravity 34.3 47.4 49.3Sulfur, PPM 10171 <6 <6 <6 <6 Cloud Point, C. −5 −10 — −17 — Aromatics,% 31.0 — — — — Mono aromatics 19.9 — — — — Polynuclear Aromatics 11.1 —— — — Total UV Absorbance: 12.6567 0.0052 — 0.0047 — UV@272 + 10UV@310Cetane Index 52.2 67 — 61 — n-DM Analysis: Aromatic Carbon, % 16.2 0.00.1 0.1 0.0 Naphthenic Carbon, % 24.0 20.6 38.1 24.7 34.0 ParffinicCarbon, % 59.8 79.4 61.8 75.2 66.0 Flash Point, Calc C. 103 72 — 58 —Aniline Point, F. 157 186 — 178 — Net Heat of Combustion, 18,455 18,890— 18,890 — D4529, KBTU/lb Distillation, D2887 IBP/5% 257/416 328/345132/169 296/314  85/149 10/30% 472/547 361/418 193/237 325/370 171/21850% 579 488 258 429 247 70/90% 617/673 549/600 288/318 516/577 270/29395/EP 698/759 626/692 328/344 601/673 298/344 Characterization 11.8912.45 11.96 12.31 12.08 Factor, Kw

Example 4

Examples 4A and 4B correspond to FIG. 8. The following process, whichexemplifies Examples 4A and 4B, was followed to produce the odorlessdiesel as illustrated in FIG. 8. A hydrocarbonaceous feedstock washydrotreated to decrease the sulfur content in the feedstock. Thehydrotreating method employed was similar to the method described inExample 1. The hydrotreated product, which had a sulfur content of lessthan 6 ppm and a total UV absorbance of 1.8774, was fed to a catalystsystem which comprised a high activity noble metal catalyst whichcomprised 0.5 wt % platinum and 0.5 wt % palladium, supported on asilica/alumina support. The temperature of the reactor was 580 F. 2915scfb of recycle hydrogen gas was fed to the reactor. 420 scfb ofhydrogen was consumed. The average pressure of the reactor was 1600 psi.The feedstock was fed to the reactor over the aforementioned catalyst,thereby producing a reaction product. The reaction product was distilledinto two streams: (1) a diesel product stream and (2) a jet productstream. The diesel product stream had a sulfur content of less than 6ppm; a total UV absorbance of 0.0038; a boiling point range of from 403F to about 768 F; and a calculated flashpoint of 120 degrees C.

Example 4B exemplifies a second run of the process using the same basemetal catalysts as in Example 4A to produce odorless diesel.

As shown in Table 4, the single stage reaction process resulted in ahydrocarbon product having an odor of less <0.5. The odorless dieselproduct may be additized with a lubricity additive dissolved in xyleneat a concentration that does not add odor to the diesel product.

TABLE 4 Base Metals Catalyst used in Hydroprocessing to Produce OdorlessDiesels ID: 4A Feed 4A Product 4B Feed 4B Product Operating ConditionsPressure, psig 1600 1604 H2 Pressure Avg, psi 1363 1386 LHSV, 1/Hr 3.03.0 Reactor Temperature, F. 580 622 Recycle Hydrogen, SCFB 2915 3115 H2Consumption, SCF 420 475 Yields: Jet. Vol. % 0.0 22.4 0.0 11.9 Diesel.Vol % 100.0 80.5 100.0 90.5 Odor Scale 5.0 <0.5 5.0 <1.5 Inspections APIGravity 38.1 39.1 38.8 40.1 Sulfur, PPM <6 <6 6.2 <6 Viscosity, cSt @ 40C. 3.400 — 2.685 — Cloud Point, C. −3 — −10 — UV Absorbance: UV@272 +10UV@310 1.8774 0.0038 2.0385 0.0110 Cetane Index 48.8 60.3 56.5 60.0Aromatics, % 18.6 — 22.2 — Mono aromatics 16.4 — 20.0 — PolynuclearAromatics 2.2 — 2.0 — Flash Point, Calc C. 89 120 59 87 Aniline Point,F. 170 192 160 258 Net Heat of Combustion, 18,589 18,742 18,620 18,965D4529, KBTU/lb Distillation, D2887 IBP/5% 283/384 403/455 231/315334/381 10/30% 412/453 482/542 355/456 405/488 50% 484 577 538 50070/90% 497/534 618/682 588/657 597/661 95/EP 552/627 711/768 684/750687/752 Characterization 11.78 12.23 11.70 12.19 Factor, Kw

Example 5

Example 5 corresponds to FIG. 8. The following process was followed toproduce the odorless diesel as illustrated in FIG. 8. Ahydrocarbonaceous feedstock having 6.2 ppm sulfur, a boiling range ofabout 231 F to about 750 F and an aromatic content of 22.2 percent byweight, as measured by SFC (Supercritical Fluid Chromatography, ASTMD5186), was fed to a reactor, which comprised a catalyst system, havinga liquid hourly space velocity (LHSV) of 2.6 1/Hr. The catalyst systemcomprised the same high activity noble metal catalyst employed inExample 4. The temperature of the reactor was 603 F. 836 scfb ofhydrogen was consumed. 3080 scfb of hydrogen was recycled to thereactor. The average pressure of the reactor was 1610 psi. The feedstockwas fed to the reactor over the aforementioned catalyst, therebyproducing a reaction product, Intermediate Products A and B.Intermediate Products A and B were the result of two separate runs. BothIntermediate Products A and B had a sulfur content of less than 6 ppm; atotal UV absorbance of 0.0044 and 0.0031, respectively; a boiling pointrange of from 165 F to about 750 F and from about 135 to about 736,respectively; and a calculated flashpoint of 38 degrees C. and 32degrees C., respectively. Intermediate product B was then fed to adistillation column wherein the distillation range was from about 317 Fto about 744 degrees F., thereby producing an odorless diesel productwhich had a sulfur content of less than 6 ppm; a total UV absorbance of0.0047; an aromatic content of less than 1.5; and a net heat ofcombustion, as determined by ASTM Method D4529, of 18,875 KBTU/lb.

The odorless diesel product may be additized with a lubricity additivedissolved in xylene at a concentration that does not add odor to thediesel product.

TABLE 5 Single Stage Process with High Activity Noble Metal CatalystsCatalyst: Pt/Pd/Silica Alumina ID: Intermediate Intermediate FeedProduct A Product B Distillation Operating Conditions Pressure, psig1610 1590 H2 Pressure Avg, psi 1489 1516 LHSV, 1/Hr 2.6 1.3 ReactorTemperature, F. 603 603 Recycle Hydrogen, SCFB 3080 3390 H2 Consumption,SCF 836 911 Yields: Jet, Vol. % 0.0 0.0 0.0 10.6 Diesel, Vol % 100.0106.5 106.4 95.8 Odor Scale 5.0 3.0 2.5 <1.5 Inspections API Gravity38.8 42.7 43.4 41.3 Sulfur, PPM 6.2 <6 <6 <6 Viscosity, cSt @ 40 C.2.685 — — 2.953 Cloud Point, C. −10 — — −9 UV Absorbance: UV@272 +10UV@310 2.0385 0.0044 0.0031 0.0047 Cetane Index 56.5 60.9 60.5 61.0Aromatics, % 22.2 — — <1.0 Mono aromatics 20.0 — — <0.5 PolynuclearAromatics 2.0 — — <0.5 Flash Point, Calc C. 59 43 38 77 Aniline Point,F. 160 177 177 182 Net Heat of Combustion, 18,615 18,908 18,923 18,875D4529, KBTU/lb Distillation, D2887 IBP/5% 231/315 169/279 135/268317/357 10/30% 355/456 327/424 312/411 379/468 50% 538 513 499 53870/90% 588/657 576/646 566/638 587/653 95/EP 684/750 674/740 670/736680/744 Characterization 11.70 12.23 12.22 12.23 Factor, K_(w)

Example 6

19.7 mg of the odorless diesel fuel composition as prepared in Example 2was injected into the combustion chamber. The fuel was injected into thecombustion chamber for 7 seconds and then ignited with a spark plug. Atthe time of injection the pressure of the chamber was 1560 bar. Thecombustion chamber was filled with gas containing approximately 15%oxygen and the remainder comprises inert gas. The gas density in thecombustion chamber was 22.8 kg/m3. The temperature of the combustionchamber was 1000 K; and the pressure of the combustion chamber was 60bar. The combustion chamber was a one-cylinder version of a 4-strokediesel engine. The injector was a second-generation Bosch Common-Railand had a nozzle diameter (single hole) of 0.090 mm and a nozzle shapeof KS1.5/0.86.

Measurements of the soot thickness were made in an optically accessiblesection of the combustion chamber. At the end of the combustion cycle,the odorless diesel fuel composition had the following results:

TABLE 6 Soot Thickness Results Sample No. 2 Ultra-Low Example 2 SulfurDiesel Odorless Diesel T₁₀ (° C.) 211 223 T₉₀ (° C.) 315 312 CetaneNumber 46 59 Aromatics Vol % 27 Less than 5 Soot Optical Thickness, KL 00 @ 20 mm from nozzle @ 30 mm from nozzle 0.4 0.4 @ 40 mm from nozzle1.8 1.4 @48 mm from nozzle 2.3 2.0 KL: kiloluminaires

As evidenced in Table 6, the odorless diesel, as prepared in Example 2,has less soot that results from the combustion of the odorless dieselthan the soot that remains when ultra low sulfur diesel is combusted.Accordingly, it may be deemed that there is a reduction in particulatematter when the odorless diesel of the present invention is employed.

Example 7 Fuel Properties of Conventional Diesel and Invention DieselUsed in HCCI Engine

TABLE 7 Comparative Comparative Diesel of the Fuel Property Unit Diesel#1 Diesel #2 Invention UV, 272 nm + Abs/L/G/cm 5.690 1.529 0.0026 10*310nm Density g/mL 0.8351 0.8462 0.835 Distillation (ASTM D86) InitialBoiling Degrees 341.4 373.8 378 Point (IBP) Fahrenheit 10% RecoveryDegrees 379.7 430.5 451 Temperature Fahrenheit 50% Recovery Degrees459.6 531.8 567 Temperature Fahrenheit 90% Recovery Degrees 605.3 617.3611 Temperature Fahrenheit Cetane 58.5 58.5 58.5 Number Heating ValueBtu/lb 18607 18733 18500 (Net) Sulfur ppm wt. <6 13 <6 Carbon wt % 85.986.7 86.1 Hydrogen wt % 14.1 13.3 13.9 Oxygen wt % 0 0 0

Example 8 Engine Test Conditions—Operated in Mild HCCI AdvancedCombustion Mode

TABLE 8 Engine Power 125 kW @ 4000 RPM Peak Torque 300 Nm @ 1500-4000RPM Number and Arrangement of Cylinders 4 cylinder in-line Displacement1.995 L Compression Ratio 14.8 Fuel Injection System Common RailTurbocharger VGT² Exhaust Gas Recycle Low pressure cooled EGR ²VariableGeometry Turbocharger

FIG. 2 shows that the diesel fuel composition of the present inventionhas lower NOx emissions when employed in an HCCI advanced combustionengine. Two comparative fuels and the diesel fuel composition of thepresent invention were injected into an HCCI engine and operated underadvanced combustion mode conditions.

The engine was operated in a range of about 1500-2250 RPM and an engineload of from about 3-8 Bar, BMEP.

Example 9 Fuel Properties of Conventional Diesel and Invention DieselUsed in Heavy Duty Detroit Diesel Engine

Heavy Duty Detroit Diesel engine was operated at Federal Test Proceduresoperating conditions as outlined in 40 CFR 86.1333.

TABLE 9 Comparison Comparison Invention Diesel #3 Diesel #4 DieselDensity, 15.56° C. 0.8379 0.8580 0.8350 Sulfur, ppm (UVF) <6 <6 <6 ASTMD5453 Carbon, wt % 85.9 87.5 86.1 Hydrogen, wt % 13.3 12.9 13.9 SFCAromatics, 21.0 35.7 2.0 wt % SFC PNA's³ wt % 3.6 7.3 0 Derived Cetane55.6 41.6 58.5 Number, IQT Heat of 18,470 18,213 18,500 Combustion,Btu/lb, net Distillation, ASTM 352 345 378 D86, ° F. Initial BoilingPoint 10% 464 428 451 50% 561 518 567 90% 628 613 611 UV, 272 nm + 2.0343.655 0.0026 10*310 nm ³Supercritical Fluid Chromatography (SFC)Polynuclear Aromatics (PNA)

FIGS. 3 and 4 show that the diesel fuel composition of the presentinvention has lower NOx and CO₂ emissions when employed in a heavy dutydiesel engine. Two comparative fuels and the diesel fuel composition ofthe present invention were injected into a heavy duty diesel engine andoperated at federal test procedure hot and cold conditions.

1. A method of reducing nitrogen oxide emissions, the method comprising(j) injecting a petroleum-derived diesel fuel composition having: (a) asulfur content of less than 10 ppm; (b) a flash point of greater than50° C.; (c) a UV absorbance, A_(total), of less than 1.5 as determinedby the formula comprisingA _(total) =A _(x)+10(A _(y)) wherein A_(x) is the UV absorbance at 272nanometers; and wherein A_(y) is the UV absorbance at 310 nanometers;(d) a naphthene content of greater than 5 percent; (e) a cloud point ofless than −12° C.; (f) a nitrogen content of less than 10 ppm; and (g) a5% distillation point of greater than 300 F and a 95% distillation pointof greater than 600 F, in an advanced combustion engine; (ii) combustingthe petroleum-derived diesel fuel in (i) in a combustion chamber of anon-spark ignited engine, wherein nitrogen oxide emissions are lowerthan those nitrogen oxide emissions when a conventional diesel fuel isemployed in a non-spark ignited engine.
 2. The method of claim 1comprising (a) injecting the petroleum-derived fuel in (i) into anadvanced combustion engine; (b) combusting the petroleum-derived fuel in(i) in a combustion chamber of an advanced combustion engine; and (c)recycling from about 20 volume percent to about 55 volume percentexhaust gas to the combustion chamber, wherein the nitrogen oxideemissions are less than 0.45 g/kWh.
 3. The method of claim 1 wherein thenitrogen oxide emissions are less than about 0.25 g/kWh at an enginespeed of 1500 revolutions per minute and an engine load of 3 Bar BMEP.4. The method of claim 1 wherein the nitrogen oxide emissions are lessthan about 0.4 g/kWh at an engine speed of 2250 revolutions per minuteand an engine load of 8 Bar BMEP.
 5. The method of claim 1 wherein theadvanced combustion engine is a homogenous charge compression ignitionengine.
 6. The method of claim 1 comprising (a) injecting thepetroleum-derived fuel in (i) into a heavy duty diesel engine; and (b)combusting the petroleum-derived fuel in (i) in a combustion chamber ofa heavy duty diesel engine, wherein the nitrogen oxide emissions areless than 4.5 g/hp-hr when the engine is operated at FTP hot.
 7. Themethod of claim 1 comprising (a) injecting the petroleum-derived fuel in(i) into a heavy duty diesel engine; and (b) combusting thepetroleum-derived fuel in (i) in a combustion chamber of a heavy dutydiesel engine, wherein the nitrogen oxide emissions are less than 5g/hp-hr when the engine is operated at FTP cold.
 8. The method of claim1 comprising (a) injecting the petroleum-derived fuel in (i) into aheavy duty diesel engine; and (b) combusting the petroleum-derived fuelin (i) in a combustion chamber of a heavy duty diesel engine, whereinthe carbon dioxide emissions are less than 530 g/hp-hr when the engineis operated at FTP hot.
 9. The method of claim 1 comprising (a)injecting the petroleum-derived fuel in (i) into a heavy duty dieselengine; and (b) combusting the petroleum-derived fuel in (i) in acombustion chamber of a heavy duty diesel engine, wherein the carbondioxide emissions are less than 550 g/hp-hr when the engine is operatedat FTP cold.
 10. The method of claim 1, wherein the sulfur content isless than 6 ppm.
 11. The method of claim 1, wherein the 5% distillationpoint as determined by ASTM D2887 is greater than 320° F.
 12. The methodof claim 1, wherein the 5% distillation point as determined by ASTMD2887 is greater than 340° F.
 13. The method of claim 1, wherein the 5%distillation point as determined by ASTM D2887 is greater than 375° F.14. The method of claim 1, wherein the fuel composition furthercomprises a lubricity additive package.
 15. The method of claim 14,wherein the lubricity additive package comprises monocarboxylic fattyacids, amides, esters, or mixtures thereof.
 16. The method of claim 1wherein the boiling point range is from about 300° F. to about 730° F.17. The method of claim 1 wherein the aromatic content is less than 10wt %.
 18. The method of claim 1 wherein the viscosity at 40° C. is lessthan 4.1 mm/Cst.
 19. The method of claim 1 wherein the net heat ofcombustion is greater than 18,000 Btu/lb.
 20. The method of claim 1wherein the advanced combustion engine is a homogenous chargecompression ignition engine.